A rare Charles I brass double-horizontal sundial plate Elias Allen, London, circa 1630-40 The 13 inch octagonal plate with inner curved 4-12-8 chapter ring and projection lines engraved for every five minutes to centre within concentric compass divided into thirty-two points each annotated with stamped abbreviations, the outer IIII-XII-VIII chapter ring with quarter divisions to inner track and minutes to outer with every ten numbered, the space between the IIII and VIII numerals signed Elias Allen Fecit, (lacking gnomon), max width 36cm (14ins); with a later purpose made eight-footed hardwood stand. Elias Allen is recorded in Clifton, Gloria Directory of British Scientific Instrument Makers 1550-1851 as moving to London from Tonbridge in Kent to take up an apprenticeship with the eminent instrument maker Charles Whitwell in around 1602. He set up business at Blackhorse Alley, Fleet St. (Horseshoe over against St. Clement's Church, Strand) in 1606 and succeeded his former Master in 1611. He gained his freedom of the Goldsmith's Company in 1612 and the Clockmaker's Company in 1633. In addition to supplying sundials, armillary spheres, marine astrolabes, ellipsographs, sectors, rules and magnetic compasses he also was a book engraver. He continued working from 'against St. Clement's' until his death in 1653. A related double horizontal dial by Elias Allen is in the collexction of the National Maritime Museum, Greenwich (object number AST 0232) which is described as having; 'two scales for reading the hours. The first is a standard scale, which is used with the polar edge of the gnomon. The second is formed by the vertical edge of the gnomon (set at the centre of the dial) and the lines of projection of the celestial sphere on to the plane of the horizon (the horizontal projection). The double horizontal dial was designed by the 17th century English mathematician William Oughtred. Elias Allen was a friend of Oughtred and he produced several double horizontal dials. They were useful not only for telling the time but also for demonstrating the motion of the sun through the day and also through the year. A number of double horizontal dials survive from the 17th century but it appears that they were not produced much after 1700. For more information regarding this dial please refer to the OUP & NMM catalogue, Sundials at Greenwich.'